C-frame construction for bulldozer



Oct. 31', 1961 J. M.- GWINN, JR 3,006,090

C-FRAME CONSTRUCTION FOR BULLDOZER Filed April 4, 1958 3 Sheets-Sheet 1 @2x/QC) C@ Oct. 31, 1961 J. M. GWINN, JR r3,006,090

C-FRAME CONSTRUCTION FOR BULLDOZER Filed April 4, 1958 3 Sheets-Sheet 2 N Q f w IN VEN TOR.

Oct. 31, 1961 J. M. GWINN, JR 3,006,090

C-FRAME CONSTRUCTION FOR BULLDOZER Filed April 4, 1958 5 Sheets-Sheet 5 INVENTOR. Jscp /zz/z'fvg J7,

afar/sf `3,0%,09'0 C-FRAME CONSTRUCTION FOR BULLDOZER Joseph M. Gwinn, Jr., Dearborn, Mich., assignor to Gar Wood Industries, Inc., Wayne, Mich., a corporation of Michigan Filed Apr. 4, 1958, Ser. No. 726,548 6 Claims. (Cl. 37-144) This invention relates generally to C-frames for mounting work attachments on tractors and more particularly to a two-section C-frame.

Heretofore, C-frames have been formed of a single rigid section because such a construction was believed to be necessary in order to provide the required strength. In a rigid construction it is very difficult to prevent some distortion of the frame during welding of the various parts. When itis considered that a `frame which measures about ten feet from front to rear end is a representative frame size, it is apparent that even a small distortion makes alignment of the mounting openings for connecting the C-frame and the tractor frame very diicult. In addition, because the bending stress in a continuous C- frame is a maximum at the mid-point of the frame, which is also at the front of the tractor, this portion of the frame must be of a maximum size and strength. Accordingly, the C-frame lifting mechanism, either a sheave and cable assembly or a hydraulic lift cylinder, which is attached to the mid-point of the CJframe, must be connected either to the rear side of the C-frame, in which case the C-frame must be spaced from the tractor front end a sutiicient distance to accommodate the lower end of the lifting mechanism; or the lifting mechanism must be connected to the top side of the frame, in which case there is a danger that the mechanism will project above the tractor a distance suticient to obscure the vision of the operator when -a hydraulic lift cylinder is used. In addition, by virtue of the overall size and weight of the C-frame, shipping problems are encountered when a one-piece construction is utilized.

It is an object of this invention, therefore, to provide an improved C-frame consisting of two separate, substantially identical sections which are pivotally connected together at their front ends forwardly of the tractor front end and are pivotally connected at their rear ends to transversely opposite sides of the tractor frame. By

vvirtue of the fact that each section is only half the length of a continuous section, the welding distortion discussed .above is reduced and the pivotal connections at the ends of each section take up the tolerances in the sections.

T he pivotal connection of the vfront end of the C-frame sections substantially eliminates any bending stresses at the front ends of the sections so that these ends can be of a reduced thickness measured fore and aft of the ractor. Because of this reduced thickness, a lifting mechanism can be attached to the C-frame at a position near the bottom of the C-frame without unduly increasing the combined fore and aft thickness of the frame and attaching mechanism. As a result, the C-frame and the dozer blade can also be located closer to the front end of the tractor thus obtaining a maximum stability and digging power for the blade. A low point of connection between the lifting mechanism and `C-frame is highly desirable when a hydraulic lifting cylinder is ernployed.

Another object of this invention is to provide a C- frame which is simple in construction, economical to manufacture, and eiicient in operation in mounting a work attachment on a tractor.

Further objects, features and advantages of this invention will become apparent from a consideration of the 3,0%,09 Patented Oct. 3l, 196i following description, the appended claims and the accompanying drawing in which:

FIGURE l is a side elevational view of a tractor provided with theo-frame of this invention and showing a dozer blade mounted on the C-frame;

FIG. 2 is a fragmentary plan view of the C-frame of this invention;

FIGS. 3, 4, 5 and 6 are enlarged transverse sectional views looking along the lines 3 3, 4 4, 5 5 and 6 6, respectively, in FIG. 2;

FIG. 7 is a fragmentary sectional view looking along the line 7 7 in FIG. 4; I

FIG. 8 is an enlarged sectional View of a central portion of the dozer blade showing the connection of the C-frame thereto;

FIG. 9 is a sectional View looking along the line 9 9 in FIG. 8;

FIG. 10 is a fragmentary side elevational View of the `C-frame and the dozer blade illustrating the assembly therewith of a lower sheave supporting block in a sheave and cable assembly `for elevating the blade; and

FIG. 11 is a view looking along the line Il il in FIG. l0. Y

With reference to the drawing, the lC-frarne of this invention, indicated generally at I0, is illustrated in FIG. l assembled with a tractor 12. for mounting a dozer blade 14 on the tractor 12 which is of the type having a body 15, an engine 16, tracks 18, `and an operators seat 20. Forwardly projecting plates '22 mounted on the tractor body at a position forwardly of the engine '16 pivotally support a hydraulic cylinder assembly 24 having a cylinder 26 and a downwardly extending piston rod 23 attached at its lower end, in a manner to be later described, to the vC-frame 10 for raising and lowering the dozer blade 14 in response to retraction and extension, respectively, of the piston rod 28. n

A The C-frame 10 is formed of a pair of complementary half sections 30 and 32, as shown in FIG. 2 which are substantially identical, being merely left` and right hand versions, respectively, of the same construction. As a result, only the left hand section 30 will be hereinafter described in detail. The section 30 consists of a pair of facing channel members 34 (FIG. 5) which are bent to the substantially half C-shape illustrated in FIG. 2 and are connected at their top and bottom sides by plate members 36 and 38 secured by welding 40 to inwardly drected anges 42 on the channel members 34. At the corner 44 of the section 3 0, a center plate 46 is secured to intermediate portions of the channel members 34 for reinforcing a portion of the section 30 which is subjected to highbending loads. The assembly of central reinforcing plates, like the plates 46, with a bent frame is the lsubject matter of my prior co-pending application Serial No. 658,827, tiled May 13, 1957, and now abandoned. By virtue of this assembly ofthe channel members 34 and the .plate members 36 and 38, the section 30 is of a box-shape in transverse cross section, as shown in FIG. 5. l

Y The end 48 of the C-frame section 30', hereinafter referred to as the rear end, carries a trunnionbase and .cap assembly 50 for pivotallly supporting the rear end of the section on the tractor 12 as illustrated in FIG. 1. Longitudinally spaced portions of the section 30 carry three socket units 52 of a particular construction for receiving a tapered pin 56 and pivotally mounting the apex of a V-strut unit 58 on the section 30. The free ends of the strut 5-8 are pivotally connected to one end of the 4dozer blade adjacent the top and bottom sides thereof in a well known manner. The three sockets 52 on each vframe section 30 and 312 provide for a ready support of the dozer blade 14vin a position either at right angles to the longitudinal axis of the tractor or inclined relative to the tractor axis in a well known manner.

At the front end 60 of the section 30 a pair of parallel substantially horizontal connecting plates 62 and 64 are secured to the channel members 34 and the plate members 36 and 3S, respectively. The plates 62 and 64 extend outwardly from the front ends of the channel members 34 and at their terminal ends are of a reduced thickness as illustrated in FIG. 6. The reduced thickness end portion of the plate 62 for the left hand section is vertically offset from the corresponding portion on the right hand frame section and the terminal ends of the plates 64 are correspondingly offset so that the end portions of the plates 62 and 64 can be arranged in a vertically stacked relation as shown in FIG. 6. In this position openings 68 in the plates are aligned for receiving an upright king pin 70. A iiat cap 72 on the king pin 70 has an opening for a cotter key 74 which extends through spaced ears 76 on the top plate 62 so that the king pin 70 is retained in position as shown in FIG. 4.

A blade mounting unit 71 has a tubular bearing portion 73 positioned between the plates 62 and 64 so that the king pin 7 0 extends therethrough. The unit 71 also includes a pin portion 75 which is formed integral with and projects forwardly from the portion 73. The portion 75 extends diametrically of the portion 73 and at its terminal end carries a retaining strap or stop bar 77 which extends diametrically of the portion 75 and is parallel with the portion 73. The strap 77 is of a length slightly greater than the diameter of the pin portion 75 so that end portions 79 of the strap 77 project-outwardly of the surface of the pin portion 75.

A mounting sleeve 81 carried by a reinforcing framework 83 on the rear side of the dozer blade 14 is of a size to tit on the pin portion 75 which provides a swivel support for the blade 14. The sleeve 81 has a pair of diametrically opposite grooves 81a arranged on opposite sides of a Vertical plane through the axis of the sleeve 81 and of a Width slightly greater than the strap 77. The grooves 81a are of a depth such that the strap end portions 79 are readily slidable therethrough when the pin portion 75 is being moved to and from a position in the sleeve S1 as shown in FIG. 8.

The reducedthickness end portions of the plates 62 and 64 are also of a reduced width so as to locate the king pin 70 as far forwardly as possible and provide an unobstructed space S (FIG. 2) between the front ends of the frame sections 30 and 32 at a location rearwardly of the king pin 70. Upright cover members 66 close the front ends of the sections 32 and 34 and constitute the sides of the space S0. Each plate 66 is provided with a forwardly and upwardly inclined groove 91 and a lateral opening 93 arranged adjacent the groove 91 for a purpose to appear later.

A pair of tubular socket or washer members 82 are secured to the cover plates 66 and the lower plates 64 so that they project horizontally from opposite directions into the space 80 at the lower end thereof. A pin 84 has its ends telescopically supported in the socket members 82 and has a central ball-shaped portion 85 adapted to be rotatably supported in a clamping sleeve at the lower end of the piston rod 28. A bar or key member 88 is secured to one cover plate 66 and to one of the plates 64 and ts in a transverse notch 90 (FIG. 7) in one end of the ball pin S4 to prevent rotation thereof in the sockets 82'.

In the assembly of the C-frame 10 with the dozer blade 14, the forwardly extending pin portion 75 on the blade mounting unit 71 is positioned so that the strap end portions 79 are movable into the grooves 81a in the sleeve S1. When the strap 77 has been moved through the sleeve 81 to the position shown in FIG. 8, the unit 71 is rotated to locate the strap 77 and the bearing portion 73 in upright positions. -The strap 77 thus coacts with the grooved sleeve 81 to provide what amounts to a bayonet 4 type joint for connecting the blade mounting unit 71 to the dozer blade 14. The king pin 70 is then inserted through the plates 62 and 64 and the bearing portion 73. The cotter key 74 is assembled with the pin 70 and the ears 76 to lock the pin 70 against accidental withdrawal.

When the -C-frame 10 is raised, by retraction of the piston rod 28, the cylinder 26 can project into the space 80 which is of a size to accommodate the cylinder 26. As a result, the dozer 14 can be raised the required distance above the ground while still achieving a tractor-dozer assembly which is of a low silhouette. The dozer blade 14 is located close to the tractor front end so that it is possible to obtain a maximum digging power from the blade. Because the C-frame 10 is formed in the two sections 30 and 32, a uniform t of the C-frame 10 on different tractors is assured. Since the king pin 70 is the only connection between the sections 36 and 32, there is no bending stress at the juncture of the sections. Consequently, the central portion of the C-frame can be made of a minimum size.

The C-frame 10 is also adapted to be raised and lowered by a sheave and cable assembly, a portion of which is shown at in FIG. l0. A sheave mounting unit 102 positioned between the cover plates 66 includes a plate portion 164 supported at its ends in the grooves 91 in the cover plates 66 and having depending tubular portions 106 which align with the cover plate openings 93. A pin 108 extends through the portions 106 and the openings 93 and has cotter pins 110 extended therethrough and positioned in grooves 112 in the portions 106 for maintaining the unit 102 in a position supported on the plates 66.

The plate portion 104 has a central socket section 114 for the semi-spherical head 116 of a bolt 118 which extends upwardly through an opening 120 in the socket section 114. At its upper end the bolt 118 is connected to a support 122 for a plurality of sheaves about which a cable 124 is trained. A spring 126 on the bolt extends between the plate portion 104 and the support 122 for maintaining the sheave support 122 in a position in which the bolt head 116 is readily shiftable in the socket section 114 to accommodate the support 122 to different moved positions of the blade 14.

A similar sheave support is arranged on the plates 22 at the forward end of the tractor and connected to a usual winch mechanism (not shown) so that the cable 124 can be manipulated so as to raise or lower the blade 14. The attachment of the unit 102 to the C-frame 10 at as low a position as the attachment of the piston rod to the C-frame 10 is not required since the upper sheave support (not shown) does not extend downwardly as far as the cylinder 26.

'It will be understood that the specific construction of the improved C-frame which is herein disclosed and described is presented for purposes of explanation and illustration and is not intended to indicate limits of the invention, the scope of which is defined by the following claims.

What is claimed is:

l. A G-frame for use in movably mounting a work attachment on a tractor, said C-frame comprising a pair of horizontal substantially half C-shape frame sections, each section having a rear end adapted to be attached to a tractor and a front end of reduced thickness, a vertical axis pivotal connection between the front ends of said sections, supporting means on said front ends disposed in a substantially facing relation rearwardly of said pivotal connection when said frame sections are pivotally connected at their front ends and are attached at their rear ends to the tractor, and means supported on said supporting means for connecting the frame to a lift' means, said connecting means comprising a member having oppositely projecting portions telescopically supported on said supporting means.

2. A C-frame comprising a pair of horizontal substantially half C-shape frame sections, each section having a rear end adapted to be attached to a tractor and a front end of a reduced thickness, a vertical axis pivotal connection between the front ends of said sections, means supported on said front ends and arranged at a position adjacent the lower side of the frame and rearwardly of said axis for connecting the frame to a lift means, said means comprising an attaching member having axially aligned oppositely projecting mounting portions, and means xed to said C-frame sections for telescopically supporting said portions.

3. ln the assembly of a tractor 'and a dozer blade having a substantially horizontal tubular member mounted rearwardly thereof in a position in which the tubular member extends rearwardly from the blade and has a pair of longitudinally extending inner grooves spaced at their front ends from said blade and arranged diametrically opposite each other, a blade mounting unit having a pin portion provided with a stop bar at one end extending diametrically of said pin portion, said bar being of a size to move through said grooves on extension of said pin portion through said tubular member to a position in which said stop bar is arranged forwardly of the tubular member and is movable to a position angularly oiset from said grooves so that it is engageable with the forward end of the tubular member to prevent retraction of the pin portion, tubular means on the opposite en of said pin portion extending transversely of the axis of the pin portion, a C-frame comprising a pair of sections having rear ends adapted to be attached to opposite sides of the tractor and front ends, and upright pin means extending through said front ends and said tubular means.

4. A C-frame for use in movably mounting a work attachment on a tractor, said C-frame comprising a pair of complementary frame sections each of which has a reduced thickness front end and a rear end adapted to be mounted on one side of the tractor, an upright king pin pivotally connecting said front ends, said front ends being of a shape to provide a space therebetween rearwardly of and adjacent said king pin when said front ends are connected and said rear ends are attached to the tractor, means on said front ends forming sockets at opposite ends of said space and means loosely mounted on said sockets and extending substantially horizontally between said front ends at a position rearwardly of and adjacent said king pin for connecting a lifting mechanism to the C-frame.

5. A C-frame comprising a pair of substantially half C-shape frame sections adapted to be arranged in substantially horizontal positions, each section having a rear end adapted to be attached to one side of a tractor and a front end of reduced thickness, a vertical axis pivotal connection between the front ends of said sections, a horizontal bail pin member arranged adjacent the lower side of the frame and rearwardly of and adjacent said axis, and socket members on said frame sections telescopically supporting the ends of said ball pin member.

6. A C-frame for movably mounting a work attachment on a tractor, said C-frame comprising a pair of complementary frame sections, each section adapted t0 extend generally horizontally along one side of a tractor and across the front thereof toward the other frame section, means at the rear end of each of said frame sections for pivotally mounting said frame sections on the opposite sides of a tractor, pivot means pivotally connecting the front ends of said frame sections for pivotal movement relative to each other about a vertical axis, said front ends being shaped to define a space therebetween rearwardly of and adjacent said pivotal connection when said rear ends of said frame sections are mounted on a tractor, means disposed in said space and mounted on the spaced portions of said front ends defining opposed recesses, one on each side of said space, and a connecting member removably supported in said opposed recesses for connecting a lifting mechanism to the C-frame.

References Cited in the file of this patent UNITED STATES PATENTS 1,038,456 Stoops Sept. 10, 1912 2,107,123 LOW Feb. 1, 1938 2,169,606 Hutchins et al Aug. 15, 1939 2,265,395 Rau Dec. 9, 1941 2,412,574 French Dec. 17, 1946 2,452,408 Washbond Oct. 26, 1948 2,604,708 Washbond July 29, 1952 2,636,289 Pryor Apr. 28, 1953 

